This invention is directed to a bearing assembly and more particularly to a bearing assembly for isolating and damping swashplate vibrations.
Current bearing assemblies are known in the art. Current designs provide a certain axial clearance due to stack up of the transfer mechanism housing (such as a pump or motor housing), cradle bearing, and swashplate tolerances. The axial clearance affects the acceleration of the swashplate.
Journal bearing support of the swashplate offers some vibrational energy isolation and damping, but also include higher friction in the rotational degree of freedom. Tapered or standard roller bearing support provides stable support with low friction, but requires a long distance between the swashplate supports which leads to high loading and bending of the swashplate. This also conflicts with hydrostatic unit design objectives to make the unit as short as possible. Cradle bearing support provides swashplate support at the most loaded areas. They optimize and minimize the maximum load and swashplate bending, but include swashplate vibrations in certain speeds related to modal properties of Kit and swashplate where the mass body vibration energy is transferred into kit and servo springs and back. This also results in higher than desired noise levels.
Needed is an assembly that provides isolation and damping like a journal bearing, stable support like a tapered or standard roller bearing, and a small installation space and support like a cradle bearing.
Therefore, an objective of this invention is to provide a bearing assembly that provides stable support, isolates and dampens vibration, and requires a small space.
A further objective is to provide a bearing assembly that reduces noise levels.
These and other objectives will be apparent to one of ordinary skill in the art based upon the following written description, drawings and claims.